1. Field of the Invention
The present invention relates to a cable sheath, more particularly to a cable sheath for a cable which is used for transmitting a pull force.
2. Description of the Prior Art
A cable sheath is used for receiving a bicycle brake cable or the like cables therein so as to provide a protective effect to the cable or its user.
A conventional cable sheath, as shown in U.S. Pat. No. 6,250,175, is a plurality of tubes which are joined to one another so as to receive a metal cable and a plastic tube of a brake cable therein. However, the brake cable is easy to be randomly wound by a remaining interior stress of its plastic tube, so that the cable is hard to be retained at an ideal position by its user. Besides, its plastic tube may crumble into small pieces as its plastic material ages, so that the pieces may obstruct the movement of its metal cable and the sheath.
Another cable sheath, as described in U.S. Pat. No. 5,899,425, is used for directly receiving a cable therein. But as the sheath is made of metal, the metal cable rubs against the sheath directly. In this way, it will make noise or get stuck by each other when in use.
Another cable sheath with a similar structure, as shown in U.S. Pat. No. 6,502,496 has an inside part and an outside part. Said parts are made of different materials in different ways. Thereby it can prevent a cable in the inside part from being scratched by the outside part. However, an adhesive is required to be applied between the outside part and the inside part. And it is more complicated to produce and assemble said sheath.
Moreover, another cable sheath of U.S. Pat. No. 6,648,376 has a sleeve inside of it. However, only part of the sleeve abuts against the sheath, so that said sleeve is easy to be separated from the sheath. In the same time, the sleeve abuts another sheath which is adjacent to it, so that the flexible angle of a joint between two sheaths is limited.
The present invention is, therefore, arisen to obviate or at least mitigate the above mentioned disadvantages.